We show that the quantum statistical mechanics describing quantum and thermal properties of objects has only the sense of a particular semiclassical approximation. We propose a more general (than that theory) microdescription of objects in a heat bath taking a vacuum into account as an object environment; we call it (h k)-dynamics (hk D). We introduce a new generative operator, a Schrödingerian or a stochastic action operator, and will show its fundamental role in the determination of such macroquantities as internal energy, effective temperature, and effective entropy. We establish that hkD can serve as an initial microtheory for constructing a modified thermodynamics. On this ground, we can explain the universality of the ratio "effective action to effective entropy" at zero temperature and its minimal value in the form h/2k. This result corresponds to experimental data obtained recently under studying a new matter state - a nearly perfect fluid. © 2010.